U.S. space agency NASA says it has lifted a controversial ban on the participation of Chinese scientists at a scientific conference in California next month.

In an email sent to VOA on Monday, NASA said "scientists of Chinese origin who initially were excluded from applying to attend the Kepler Science Conference at NASA's Ames Research Center next month now are able to apply."

The U.S. space agency says its initial decision to bar access to the Chinese scientists was "unfortunate" and based on a "misinterpretation" of government policy.

Earlier this month, a group of academics organizing the conference said they reluctantly denied the registrations of six Chinese nationals because of a NASA moratorium.

The organizers said the U.S. space agency banned visits to NASA facilities by citizens of China and several other nations in March, when a new U.S. law took effect. The law restricts foreign access to NASA facilities due to national security concerns.

The organizers said they only learned about the NASA ban in late September and denounced the legal restrictions behind it as "deplorable." Some U.S. scientists had said they would boycott the conference to protest the exclusion of the Chinese academics.

NASA says the policy concerning foreign access to its facilities was "clarified and the decision corrected" once the federal government reopened last Thursday after a 16-day partial shutdown.

A Republican lawmaker who drafted the NASA restrictions had appealed to the space agency to make that clarification.

Frank Wolf sent a letter to NASA on October 8, saying the law does not ban all Chinese individuals from entering NASA facilities. Instead, he said it "primarily restricts bilateral ... (NASA) activities with the Communist Chinese government or Chinese-owned companies."

In a report published Saturday, China's state-run Xinhua news agency said NASA sent a letter to the six Chinese scientists, informing them that their applications for the conference were "being reviewed for clearance."

Xinhua said NASA wrote that it hopes the Chinese nationals "will be able to join us" at the gathering. The news agency said it obtained a copy of the letter from one of the scientists who refused to be named.

China had accused NASA of "discriminatory behavior" for the earlier decision to bar the scientists. It said Beijing believes that academic or scientific research activities "should not be politicized."